The effect of active travel interventions conducted in work settings on driving to work: A systematic review

Background: There is increasing interest in promoting active travel for transport and health benefits. Whilst epidemiological evidence of associations between active travel and health outcomes exists intervention studies are lacking. Systematic reviews have been conducted on the effectiveness of active travel interventions, but none have focused on interventions in the work setting only. Objective: The objective of this study is to systematically assess the effectiveness of active travel interventions, only including randomised controlled trials or controlled longitudinal studies, conducted in a work setting for increasing employee physical activity levels and decreasing relatively inactive forms of transport (e.g. driving) to inform interventions promoting active travel. Methods: Data were sourced from English and non-English articles using 10 databases and by contacting experts. Unpublished literature was sought via databases including conference proceedings, doctoral theses and a text book. Data were extracted independently by two authors and a third author adjudicated where there was no consensus. The same two authors assessed studies for risk of bias. Findings: Twelve articles were identified for inclusion. Results could not be pooled for a meta-analysis since outcome measures were heterogeneous. Given that 10 out of the 12 studies found positive results for increasing active travel or decreasing driving to work, workplace active travel interventions look promising. However, the evidence was not strong since the small number of controlled studies included were at high risk of bias. Conclusions: Evaluations of active travel interventions with robust study designs such as controlled before-after studies and cluster-randomised controlled trials are needed to provide stronger evidence, and pragmatic approaches to implementing controlled trials will need to be considered. Consensus on outcome measures for intervention studies would assist future reviews and meta-analyses. Since most active travel interventions at present are not controlled studies, reviews which include uncontrolled studies are another important source of evidence to inform policy and practice.